Five tips for keeping your home cool in extreme heat

In summer, a poorly insulated house allows heat to build up inside, while letting cool air escape, so it’s important to fully insulate your whole home.

In the winter, the Energy Saving Trust reports that a quarter of all the heat in an insulated home is lost through the roof¹ . In the summer, that same uninsulated roof will allow hot air in and rapidly make your home a very hot and sticky place to hang out in.

So, loft insulation is essential for preventing heat from penetrating into your living spaces in summer and escaping in winter.

Add insulating materials, such as fibreglass, wool or polystyrene panels, to keep the heat out of your home on hot days.

Well-insulated walls play a vital role in helping to keep your home cool in extreme heat too.

If your home was built during or after the 1920s, it may well have cavity walls. This is where the wall is made of two layers of brick with a gap in between. Cavity walls are great for damp prevention, but that cavity can draw in hot and cold air from the outside, depending on the season. You can insulate a cavity wall by injecting the internal space with expanding insulating foam.

Alternatively, you can insulate cavity and non-cavity walls by fixing insulating panels to the internal or external side of the wall.

Whichever insulating method you choose, it should help your home to remain at a comfortable temperature all year round.

Outdated or poorly-sealed windows are a major source of heat gain in summer, making it harder to keep your home cool. Replacing them with modern, energy-efficient windows should significantly improve the insulation in your home and help to keep it cool.

If you have rooms in your loft, consider replacing your old roof windows with the latest energy efficient model. This will reduce the heat coming in from outside and improve the ventilation in your loft space, making it feel fresher.

Combined with VELUX heat protection accessories, such as anti-heat blinds or blackout shutters, you can block the sun’s rays before they reach the glass, helping to reduce indoor temperatures by up to 5°C, depending on the model you choose.

And, replacing old windows won't just help you to keep your home cooler in summer; they will help to keep it cosy in winter too. This long-term investment will make your whole home more energy-efficient and comfortable all year round.

Here are five ways you can reduce the temperature in your home during extreme heat without resorting to air conditioning:

Cross ventilation is a simple and effective natural ventilation method for quickly cooling your home without the need for fans or air conditioning.

It works by opening windows on opposite sides of your home to create a through-draft, which draws warm air out and allows cooler air to flow in. Open windows in your kitchen and your living room, for example, to encourage air to move around. This works particularly well at night when the outside air is cooler and will reduce the heat in your home as much as possible before another hot day.

The stack effect is another natural way to cool your home, taking advantage of the fact that hot air rises. Open windows at different heights to create vertical airflow. For instance, open an upstairs window and a roof window at the same time. This will pull in cooler air from below while pushing warm air out through the top of your home. Again, it’s most effective at night, when outdoor temperatures drop.

Blocking direct sunlight before it enters your home is one of the simplest and most effective ways to keep your rooms cool. Use external blinds or awnings to reduce solar heat gain through windows and other glazed areas.

If you have roof windows, exterior anti-heat blinds and shutters are especially effective:

• Anti-heat blackout shutters provide a sturdy aluminium shield that will cool your space by up to 5°C, block out light and protect your roof from harsh weather.
• Anti-heat blackout blinds are made of soft, durable mesh that blocks out light and heat and improves insulation.
• Anti-heat blinds are made of soft, breathable mesh that reduces heat and glare while still letting daylight in — perfect for home offices or living spaces.

All these accessories can be automated using VELUX ACTIVE with NETATMO, which adjusts blinds and shutters based on indoor temperature, humidity and CO₂ levels, keeping your home cool with minimal effort.

As UK homes rarely have air-conditioning systems that cool, heat and replace indoor air, extractor fans, most often found in the wall or ceiling of a kitchen and bathroom, are great for expelling hot, humid and smelly indoor air and maintaining a flow of fresh air into your home.

Heat sources, such as incandescent light bulbs, and electronic equipment, like televisions, also increase indoor temperatures.

Replace incandescent light bulbs with LED bulbs that generate less heat and use less energy and try not to switch them on when outdoor heat levels are peaking.

Switch off devices from the wall so they are not on standby mode and remember to unplug chargers when not in use too.

Keeping your home cool during hot weather also means adjusting your daily habits.

From smarter appliance use, to choosing cooling clothing, to surrounding yourself with plants, small changes make a big difference for staying comfortable on super-hot days.

Using appliances that produce heat, such as ovens and washing machines, during the cooler parts of the day will help reduce the amount of heat you generate indoors.

You could also switch to using appliances that generate less heat, like microwaves and slow cookers.

And, give your tumble drier a rest and air dry your clothes on an airer outside if you can.

Wear loose, light and breathable clothing that allows for better air circulation around your body during a heatwave:

• Cotton absorbs sweat and allows your skin to breathe, making you feel colder.
• Linen is one of the most breathable fabrics. It provides excellent ventilation and dries quickly, helping keep you cool.
• Rayon is a lightweight fabric that mimics the breathable properties of cotton and linen.
• Bamboo is a naturally breathable and antibacterial material that is very comfortable in hot weather.

Other practical tips for optimal comfort:

• Use cotton or linen sheets to keep you cooler at night.
• Drink a glass of water before bed to stay hydrated.
• Take a cool shower before bed to regulate your body temperature or apply a wet flannel to your neck and wrists for an immediate cooling effect.

Plant trees and shrubs around the outside of your home to help shade it on hot days. They will also cool the surrounding air and provide natural insulation.

Deciduous trees are particularly great because they provide dense shading in summer, while allowing sunlight to warm your house in winter. Before planting trees near your property, speak to a UK-qualified gardener or arborist, as some root systems may affect foundations or pipes.

Indoors, plants regulate temperature and improve air quality too. Here are some of the best houseplants for this:

• Ficus Benjamina: acts as a filter unit for air toxins.
• Sansevieria: great for beginners as it’s relatively low maintenance, this plant will purify your air.
• Dracaena: helps eliminate formaldehyde and other common toxins found indoors.
• Aloe Vera: another easy-to-care for plant that has great air purifying properties.
• Areca palm: excellent for humidifying the air and creating a fresh atmosphere.